Screw-driver.



No. 724,154. Y l I PATENT-ED MAR. y31, 1903.

H. BBRQUIST. v

SCREW DRIVER. APPLIUATION FILED 00131. 1902.

y /wgw Stimme?,

Tn: Ncnms PETERS co. Pnomume. wnsmumow. D. c.

UNITED STATES PATENT OFFICE.

HENRY BERQUIST, OF ST. CROIX FALLS, WISCONSIN.

SCREW-Dawn.

SPECIFICATION forming part of Letters Patent No. 724,154, aat-ed Marchal, 190e.

Applicatie mea october s1. 1992. seria No. 129,595. (No model.)

To d/ZZ whom t may concern:

Beit known that I, HENRY BERQUIST, a citi- 'zen of the United States, residing at St. Croix Falls, in the county of Polk and State of Wisconsin, have invented new and useful Improvements in Screw-Drivers, of which the following is a specification.

This invention relates to screw-drivers, and has for its object to provide a screw-driver of preferred construction and the blade of which is so arranged that it will firmly grip the head of the screw to prevent an accidental displacement thereof.

As is well known, considerable trouble is ex-Y perienced with the ordinary form .of screwdrivenwhen the screw is being driven into hard wood, owing to the fact that the blade will continually slip from the groove in the screw, ,necessitating a great pressure to hold the blade in proper relative position with the screw-head. By utilizinga construction similar to my device the screw-head will be firmly engaged and the liability of the blade becom-A ing detached from the screw-head accidentally will be obviated.

The invention consists in the peculiar construction of blade, to be described hereinafter and illustrated in the accompanying drawings, in which-- Figure lis a side elevation of a screwdriver blade and a fragmentary view of a screw, showing the screw-driver and screwin proper relative position. Fig. 2 is a plan view of the screw-driver blade and shank. Fig. 3 is an end view of the screw-driver blade. Fig. 4 is a transverse sectional view on the line 4 4 of Fig. 2.

The reference-numeral l designates the shank of the screw-driver, which can be secured to a suitable handle. The lower end of the shank terminates in a flat blade 2, between the longitudinal edges of'which is provided a right-angular elongated rib 3, which vof the blade twisting out of the screw owing to the resistance thereof will be diminished.

It will be apparent that the sharp edgeof the rib will readily sink into the Wall of the groove f ofthe screw, and owing to the fact that the edge is acute or inclined the blade will be forced against the side w`all of the groove, and thereby hold itin proper relative position with relation to the screw head. Additional strength will be imparted to the blade in view of the fact that the rib yruns the entire length thereof, thereby relieving the strain caused by turning the same through the medium of thehandle.

Having thus described the invention, what is claimed as new, and desired to be secured by Letters Patent, is-

l. A screw-driver blade, having a longitu# dinally-arranged rib thereon provided with a sharp end edge.

2. A screw-driver blade having a longitudinally-arranged rib intermediate the sides thereof, the end of the rib terminating a short distance above the end of the blade and having a sharp edge designed to engage the side wall of a screw-groove.

3. A screw-driver blade having a cutting edge formed therewith and arranged at an angle inclined back from the end of the blade.

. In testimony whereof I affix my signature in presence of two witnesses. A

- HENRY BERQUIST.

Witnesses:

FANNIE S. HEILLER, HARRY D. BAKER.`V 

